The objectives of this project are to provide essential biological substrates required for the study of genetic susceptibility to cancer. The offeror will initiate transformation of lymphocytes with Epstein-Barr virus in order to establish long term cultures of lymphoblasts. These cells will subsequently be used to extract DNA for genetic marker studies. DNA will also be extracted directly from the granulocytes and lymphocytes in whole blood, from cultured fibroblasts and tumors, and from fresh tumor material. The DNAs obtained from these assays will be used by investigators in the Environmental Epidemiology Branch (Family Studies Section) and the Clinical Epidemiology Branch (Clinical Genetics Section) in ongoing studies of cancer susceptibility due to genetic etiology.